The effect of hair pigment on the incorporation of fatty acid ethyl esters (FAEE).

AIMS: The objective of the current study was to determine whether FAEE incorporation is affected by hair pigmentation. METHODS: Black hooded LE rats were injected intraperitoneally daily with ethanol. Prior to dosing, black and white patches of fur were shaved and analyzed for baseline levels of FAEE using an adapted extraction procedure and GCMS method. Once the shaved 'patches' had grown back they were re-sampled along with hair outside the 'patches', referred to as 'no patch' hair, and tested for post-treatment FAEE levels in the same manner. Blood was also sampled for pharmacokinetic analysis of ethanol. RESULTS: Total FAEE levels were significantly higher in post-treatment hair (black and white) compared to baseline (pre-treatment) levels. Total FAEE levels were also significantly higher in post-treatment 'patch' hair (black and white) compared to 'no patch' hair. No significant differences were found between post-treatment black and white hair. The FAEE profiles were similar between black and white hair, with FAEE levels being highest for ethyl myristate, followed by ethyl stearate, palmitate, and then oleate. CONCLUSION: FAEE incorporation into hair does not appear to be affected by hair pigment, which is in congruence with what is known about the chemistry of drug-melanin interactions. This is important in avoiding potential bias and discrimination in the interpretation of alcohol abuse based on hair color.

Gap analysis of pediatric reference intervals related to thyroid hormones and the growth hormone-insulin growth factor axis.

Efficacy of laboratory medicine in assisting attending physicians in their diagnostic and follow-up endeavors is intimately linked to an access to meaningful and reliable reference values. Pediatrics is particularly sensitive to this problem as the processes, associated with growth and development, are imposing rapid discontinuous changes on the physiology of the individuals. Some developmental stages are more critical than others. The neonatal and the pubertal periods, for which we lack reference ranges, are two such examples. Beyond biological considerations, we realize that, over the last 2 decades, technology has evolved, both at the analytical and reagent levels. This technological evolution inexorably leads to the need in redefining reference values. It is for this reason that a group of clinical and medical biochemists have joined their efforts in creating the Canadian Laboratory Initiative in Paediatric Reference (CALIPER) which objective is to define a pan-Canadian set of reference values from birth to late adolescence. To illustrate the need of such a venture, a brief gap analysis for biochemical variables related to the thyroid function, and the growth hormone-insulin-like growth factors axis follows.